TAKE A KNEE: When he injured his right knee last week in practice, it was feared Giants cornerback Terrell Thomas would need season-ending surgery, but now he has been told he could be back on the field in time for Week 1 of the NFL season. Photo: Neil Miller

ALBANY — The Giants open their regular season in one month. There is a chance Terrell Thomas will be lining up at cornerback that night against the Cowboys.

That is not a misprint. The long-awaited news on Thomas arrived yesterday and it unquestionably can be characterized as a best-case scenario.

“I think it is,’’ coach Tom Coughlin said after practice on a humidity-free, sun-splashed afternoon at the University at Albany.

The pleasant breeze seemed to blow in good tidings for the Giants. Thomas is headed back to begin a rehabilitation program on his right knee, which was feared to have suffered another season-ending injury to his anterior cruciate ligament when, on July 29, he slipped while covering Domenik Hixon and the next day experienced swelling in the knee. Thomas missed the entire 2011 season with a torn right ACL and he went down this summer with what the Giants reported as another injury to the ACL. If further surgery had been needed, his 2012 season would have been overbefore it started.

Thomas yesterday received the news he wanted to hear after a third opinion, from renowned orthopedic surgeon Dr. James Andrews in Birmingham, Ala. That opinion was in line with the findings of Thomas’ own surgeon, Dr. Arthur Ting in California, and the Giants’ medical team.

“He’s coming back to camp, he’ll jump into a rehab program, we’ll watch him very, very closely. We’ll hopefully accelerate his strengthening of the knee and see how soon he can join us and we’ll hope for the very best,’’ Coughlin said.

Thomas did not have a diagnostic arthroscopy, which should help his recovery time. The Giants are offering no timetable for a possible return, but it’s safe to say if all goes well, Thomas could perhaps be back on the field in a month.

“If a lot of the fibers are intact and they feel its stable then they start him on a program of rehabilitation and generally it’s very similar to rehabbing a basic diagnostic arthroscopy, which is, generally speaking, four to six weeks you’re talking about to recover,’’ Dr. Stephen Hunt, orthopedic surgeon and sports medicine specialist at Atlantic Sports Health at Morristown (N.J.) Medical Center told The Post. Dr. Hunt has not examined Thomas and was speaking about similar ACL scenarios.

“We are very relieved at the news from Dr. Andrews,” Doug Hendrickson, Thomas’ agent, wrote in an email to The Post. “Terrell is beyond happy as he is looking forward to helping his teammates get back to the Super Bowl.”

Hendrickson added the anticipated time frame for Thomas’ return was four-to-six weeks.

Thomas is expected back in camp today and will immediately begin his rehab regime.

“He’s gonna jump in there and I’m sure he’ll go hard,’’ Coughlin said. “He feels very positive about it. He told me before he left he really doesn’t have any pain, does not feel instability, the knee was not swollen so he went down and Dr. Andrews pretty much agreed with what the other doctors had said and what they felt was: Let’s try to rehab him and see if we can get him right back on the field.’’

The Giants will not rush Thomas back, as he is a key ingredient in their defensive scheme. He was a shut-down corner in his two years (2009 and 2010) as a starter and also a playmaker, with had 10 interceptions. Contingency plans were already being made, fearing that he might be lost for another season. Without Thomas, the hope was second-year Prince Amukamara could step into a starting cornerback role. On the day the Giants got the news they wanted to hear about Thomas, Amukamara sat out practice with what Coughlin said is “a little bit of a hamstring.’’

Of course, there are no guarantees Thomas’ right knee will hold up, considering he already has had two ACL repairs on it (the first in 2005 at USC, the second a year ago) and he did suffer some sort of trauma to the ligament this time around.

“It would be wonderful if he went out there and did all these zig-zags and came off and had no swelling, felt great and said, ‘OK what’s next,’ ’’ CoughIin said. “I can’t tell you what the answer’s gonna be when he tries to do all that.’’